Water resistant push piece for diver&#39;s watch



Jan. 9, 1968 K. WENGER WATER RESISTANT PUSH PIECE FOR DIVER'S lWATCH Filed Jan. 17, y196'? IIITIE United States Patent O 3,362,153 WATER RESISTANT PUSH PIECE FOR DIVERS WATCH Karl Wenger, Chambesy, Switzerland, assigner to Fabrique de Couronnes Boninchi S.A., a company of Switzerland Filed Jan. 17, 1967, Ser. No. 609,938 Claims priority, application Switzerland, Feb. 1, 1966, 1,401/ 66 6 Claims. (Cl. 58-63) ABSTRACT OF THE DISCLOSURE Water resistant push piece for a divers watch comprising a part movable axially, mounted slideably on a tube fixed to the body of the case, enveloping partially this tube, and having a central core penetrating the tube, at least one element having water resistance between the tube and the core and a return spring pushing the movable part towards the outside.

In the water resistant push pieces used at present for divers watches, it is necessary to use a rather powerful return spring so that the push piece is not compressed by the high pressures found at the great depths of a dive. This solution has evidently the disadvantage of necessitating an excessively strong pressure of the push piece when the latter is actuated out of the water or at shallow depth.

The present invention proposes measures appropriate to improve these push pieces while permitting weaker springs t-o be used for equal depths or greater depths to be reached with the present springs.

The push piece according to the invention is characterized by the fact that the annular space comprised between the core and the part surrounding the said movable part communicates with the outside, at the same time by a space left between the enveloping part and the tube and by at least one opening formed in the upper part of the enveloping part and of suicient dimension so that during the dive the water penetrates easily into the said annular space, so that the pressure of water at the interior of this space increases at the same time as the pressure of water outside the push piece and adds its effect to that of the said spring.

The accompanying drawings represent, by way of example, three embodiments of the invention.

In FIGURES l to 3, the same reference characters designate th`e same elements, the latter having nevertheless some diflerences of form. FIGURE 1 shows a push piece comprising a tube 1 preferably having an enlarged middle section screwed in the case 2 of a divers chronograph, the water resistance being assured by a packing of joints 3. On the tube is mounted the head of the push piece 4 comprising a central cylindrical core 5, sliding in a bore 6 of the tube 1 below the lower end of an upper housing in said tube 1 and a cylindrical wall 7 provided with utes 8 enveloping partially the tube 1 provided with identical flutes 9 engaging in the flutes 8 in a manner to prevent rotation of the head of the push piece, there being some play nevertheless left between the fiutes 8 and 9 to permit the water to penetrate into the annular space 10 comprised between the core 5 and the wall 7 of piece 4. In the core 5 is screwed a rod 11 for the control of inner members of the chronograph. A helical spring 12 is compressed between the end of the core 5 and a lower edge 13 of the tube 1. The water resistance of the push piece is assured by two annular joint packings 13 and 14 disposed in the housing formed in the upper part of ice tube 1 and maintained axially by a washer 1S inserted at the upper end of the tube.

During a dive, the water penetrates into the space 10 and the pressure in this space increases at the same time as the outside pressure acting on the head of the push piece. Its effect thus adds to that of the spring 12, thus permitting a weaker spring to be used than if the latter must support all alone the outside pressure. Nevertheless, during a rapid dive, the exterior pressure increases more quickly than the pressure at the interior of the space 10, the flutes 8 and 9 acting as bales slowing down the entry of the water into the space 10. To remedy this disadvantage, one or more lateral holes 16 are provided through the wall 7 of the push piece, these holes being of sufficiently large diameter to permit a rapid entry of the water into the space 10.

In the embodiment shown in FIGURE 2, the core 5 of the head of the push piece is more elongated, the spring 12 being disposed around the core between the upper part of the head 4 and the bottom of a socket 17 housed in the tube 1 and holding axially the packing joints 13 and 14 against a lower shoulder of the tube. This solution has the advantage of permitting an easy mounting and dismounting of the push piece, in particular an easy replacement of the packing joints 13 and 14. Since the socket 17 is not inserted in the tube but simply maintained by the spring 12, against an upper shoulder of the tube, it can be easily removed after unscrewing the screw 11.

In a third embodiment shown in FIGURE 3, the water resistant packings 13 and 14 are no longer mounted in the tube, but on the core 5 of the head of the push piece. This core has for this purpose .a reduced lower section S on which are introduced the packings 13 and 14, the latter being then maintained axially by a washer 19 fixed by means of a shoulder of the screw 11. This solution permits, during a repair, to remove the packings 13 and 14 with the head of the push piece. The return spring 12 is disposed as in FIGURE 1.

Numerous variants are possible in the arrangement and fastening of the joints and in the arrangement of the return spring.

What is claimed is:

1. Water-tight -push piece assembly for divers time piece comprising a tru-be secured to the case of said time piece, an axially movable push piece head having a peripheral wall partially surrounding said tube and a core spaced from said wall thus dening an annular space therebetween, said core being slidingly mounted in said tube; said wall and said tube having flutes, the utes of said wall enveloping the flutes of said tube and being engaged therewith to prevent rotation of said head, said wall having at least one lateral opening in the upper part thereof making said space communicate with the outside; at least one water-tight packing between said tube and said core, a spring in said tube for urging said push piece head outwardly and clearances between said wall and said tube for making said space communicate with the outside, whereby, during a dive, water can penetrate in said space so that water pressure inside the space can increase at the same time as the water pressure outside the push .piece head and add its effect to that of said spring thereby making possible the use of a weaker spring to push said piece head outwardly.

2. Assembly according to claim 1, wherein said tube has a lower edge and said spring is compressed between said lower edge and said core.

3. Assembly according to claim 1, wherein said tube has an enlarged central section surmounted by an upper housing, said housing having therein joint packings and a washer securing said packings axially therein.

4. Assembly according to claim l, wherein said tube has a socket in the upper part thereof surrounding said core and said spring is disposed around said core in said socket.

5. Assembly according to claim 4, wherein said tube has an upper peripheral shoulder about midway therein and a lower shoulder spaced therefrom, said socket resting against said upper shoulder, and packing joints in the space between said shoulders.

6. Assembly according to claim 1, wherein said core has a reduced lower section and a rod screwed in for the command of inner members of said time piece and has a shoulder in the upper part theerof, there being packings around said reduced section and a washer maintaining said packings axially, said washer being secured in place by said shoulder, said spring bearing outwardly against said washer.

References Cited UNITED STATES PATENTS 2,202,114 5/1940 Mori 58-90 2,391,803 12/1945 Simon 58-90 FORETGN PATENTS 234,157 9/ 1944 Switzerland.

245,133 6/ 1947 Switzerland.

248,255 1/ 1948 Switzerland.

254,303 12/ 1948 Switzerland.

350,244 12/1960 Switzerland.

ROBERT S. WARD, IR., Primary Examiner.

RICHARD B. WILKINSON, Examiner.

M. LORCI-I, Assistant Examiner. 

